code: def test_IsotonicRegression(self):
      # disable at this moment
      return
      """
          data = np.abs(np.random.randn(100))
          data = data.cumsum()
          df = pdml.ModelFrame(np.arange(len(data)), target=data)
  
          mod1 = df.isotonic.IsotonicRegression()
          mod2 = isotonic.IsotonicRegression()
  
          # df.fit(mod1)
          # mod2.fit(iris.data)
  
          # result = df.predict(mod1)
          # expected = mod2.predict(iris.data)
  
          # self.assertIsInstance(result, pdml.ModelSeries)
          # self.assert_numpy_array_almost_equal(result.values, expected)
          """
  
file_path: pandas-ml/pandas_ml/skaccessors/test/test_isotonic.py
imports: import numpy
  import sklearn.isotonic
  import pandas_ml
  import pandas_ml.util.testing
label_desc: Use image node_id 4 for calling the TestIsotonic obj's underlying member method code with example usage: obj.test_IsotonicRegression() without return types